Material feeding mechanism



May 2, 1939- c. E. HARRISON MATERIAL FEEDING MECHANISM x Original Filed Jan. 16, 1935 Patented May 2., 1939 UNITED STATES PATENT OFFICE MATERIAL FEEDING MECHANISM Original application 2,034, now Patent 2,100,

January 16, 1935, Serial No.

741, dated November 30, 1937. Divided and this application September 22, 1937, Serial No. 165,042

5 Claims.

This application is a division of my co-pending application Ser. No. 2,034, filed January 16, 1935, for Material feeding mechanisms, now Patent 2,100,741, granted November 30, 1937, and the invention herein involved relates to ram cylinders of the type employed in material feeding devices.

Rams and the cylinders therefor which are constructed in the usual manner with smooth 10 continuous contacting surfaces, have been found,

under certain conditions, when employed for feeding purposes, to bind to such an -extent that serious damage occurs to the operating parts. This binding action usually occurs after the de- 15 vice has been in operation for a considerable period of time and has become worn so that a substantial clearance exists between the rams and cylinders. Due to this clearance, siftings are more readily drawn between the ram and 20 cylinder when the former recedes after a feeding operation. The ram also tilts slightly about a transverse axis during its movement in the cylinder. Because of this tilting action these materials have a tendency to accumulate more 25 rapidly near the outer end of the cylinder and upon successive operation of the ram these materials become packed to such an extent as to form a non-compressiole scale in the form of a wedge, tapering downwardly toward the inner 30 end of the cylinder. Upon successive operations of the ram additional materials are drawn into the cylinder and finally the mass becomes so packed that the ram cannot be withdrawn after a feeding stroke, and as a result serious damage 35 occurs to the operating parts.

One object of the present invention is to provide an improved ram cylinder construction which will eliminate the above mentioned difliculties.

A more specific object is to provide in a ram cylinder of the stated character longitudinally extending grooves, or other irregularities in the inner surface thereof, whereby a broken surface is presented to the associated ram which pre- 45 Vents binding of the latter due to siftings.

Other and further objects will become apparent as the description of the invention progresses.

f the drawing:

Fig. 1 is a side elevational view partly in sec- 50 tion of a ram and cylinder assembly employing the present invention.

Fig. 2 is a plan view partly in section, of a ram cylinder showing spiral grooves provided in a portion of the inner surface thereof.

Fig. 3 is a plan view partly in section of a modification of the structure shown in Fig. 2, and

Fig. 4 is a plan view of a still further modification of the structure shown in Fig. 2.

Referring to the drawing, the numeral I indicates generally one form of ram and ram cylinder to which the present invention may be applied. This general construction is shown and described in United States Patent No. 1,958,639, granted to Herbert E. Preston, and assigned to the American Engineering Company, to which reference may be had for a full disclosure thereof.

Ram 2 comprises a fuel feeding portion 4, which in the present instance is secured to a base 5 by any suitable means, such as by bolts Ii, and is operated by a crank shaft 'I through a connecting rod 8 extending through the outer or right hand end of the ram and pivoted to the base portion 5 thereof, as shown at 9. Thus, upon rotation of crank 1, ram 2 will be reciprocated in the cylinder 3. Cylinder 3 is provided with a liner element ll' constructed of wear resisting material. The portion of the ram box beneath the hopper I2 is also provided with wear plates I3. Cylinder 3 also has provided near the right hand end thereof a band of packing I4 held in place by a metallic ring I6, and a second ring I1 extends between the packing I4 and the end of the cylinder. These elements are held in place in any suitable manner, such as by bolts I8, as shown in Fig. 1.

Referring to Fig. 2, it is seen that the liner element I I of cylinder 3 is provided with a series of approximately longitudinally disposed, spiral grooves 26. The side walls of these grooves diverge slightly from right to left (Fig. 2) to facilitate the removal of the siftings accumulating therein. By this construction it is seen that the grooves 26 provided in the liner element II' present a broken surface to the siftings drawn between the ram and its cylinder, andthus packing ofthe siftings into a hard sealy mass, which eventually causes binding of the ram, is prevented. Y

In Fig. 3 the liner element II" is shown provided with a series of longitudinally disposed grooves 2l. The side walls of these grooves also diverge slightly from right to left of the cylinder. In this construction the grooves are 'straight rather than spiral, as shown in Fig. 2.

In Fig, 4 the liner element I,I"' is shown provided with a series of projections 28 instead of the spiral or straight grooves 26 and 21 shown in Figs. 4 and 5 respectively. By this construction the contacting surface is broken up into a Y series of spaced points, and packing of the siftings trapped between the ram and the cylinder is reduced to a minimum.

It is understood that when no liners are employed the grooves 26, 21, or the projections 28 shown in Figs. 2, 3 and 4, may be provided in the cylinder wall proper.

From the foregoing description, it is seen that because a broken surface is presented to the siftings trapped between the ram and its cylinder the action of the ram on such siftings is momentary rather than continuous, and as a result the siftings cannot be compressed into a non-compressible scaly mass which nally causes binding of the ram and damage to the associated parts. These constructions are especially desirable in connection with stoker furnaces wherein continuity of service is of great importance. By eliminating binding of the rams in such devices the life of the operating parts is not only prolonged, but efficient operation is maintained without danger of binding of the parts or damage to the operating elements.

While the embodiments herein described are admirably adapted to fulll the objects primarily stated, it is to be understood that the invention is not to be limited thereto since it may be ernbodied in other forms, all coming within the scope of the claims which follow.

What is claimed is:

1. A ram cylinder of the class described, having an annular ram engaging surface provided with longitudinally disposed indentations, said indentations forming a series of irregularities in the said ram engaging surface whereby contact with the ram adapted to operate in said cylinder is made only at spaced points.

2. A ram cylinder having an annular ram engaging surface provided with a series of grooves extending longitudinally thereof in spaced relation, and the side walls of said grooves diverging toward the inner end of said cylinder.

3. A ram cylinder having an annular ram engaging surface provided with a series of spiral grooves extending approximately longitudinally thereof.

4. A ram cylinder having an annular ram engaging surface, provided with a series of spiral grooves extending approximately longitudinally thereof, and the side walls of said grooves diverging toward the inner end of said cylinder.

5. A ram cylinder of the class described, having an annular ram engaging surface provided with a series of grooves extending longitudinally L thereof, and the said ram engaging surface having an annular groove provided near one end thereof adapted to receive packing material.

CLIFFORD E. HARRISON. 

